Schwartz on Freedom: Vacuity or Stirnerism?

Looking again at Barry Schwartz's The Paradox of Choice, I'm struck by something Virginia Postrel picked up on in her Reason review, which is that Schwartz's argument turns on a false opposition between freedom and commitment. I tripped up on the same passage Virginia noted:

In the context of this discussion of choice and autonomy, it is also important to note that, in many ways, social ties actually decrease freedom, choice, and autonomy. Marriage, for example, is a commitment to a particular other person that curtails freedom of choice of sexual and even emotional partners.

To which Virginia sensibly responds:

So gays who cannot legally marry their partners are somehow freer than heterosexuals who can? There’s something deeply wrong with this understanding of choice. Freedom to choose must include the freedom to commit.

But I think there is something even more deeply wrong with Schwartz's opposition of freedom and commitment than Virginia brings out. It is either trivial, or commits what I will call the “Stirnerite fallacy.”
Most of the time, Schwartz seems to be operating under a notion of freedom as opportunity or ability. In this sense, if a new variety of jam comes on the market, then my freedom has increased, because now I have the opportunity to buy it. Conversely, any reduction in my feasible set of alternatives is a reduction of freedom. But this is a completely formal notion devoid of any real content. If I set out 5:00 pm to drive from DC to Indiana, then, by the time I make it to Ohio, the possibility of arriving at New York City by midnight has dropped out of my set of alternatives. It trivially follows that my “commitment” to get to Indiana requires that I forgo some alternatives. But, even so, it doesn't follow that my feasible set is now diminished. By the time I get to Indiana, there will be a large number of places I could get to by midnight that I couldn't have reached in that time had I stayed in place in DC. Or, if I get a new job, in a different building, my options for lunch will have changed. I can no longer go to the place I liked around the corner from my old building (too far away). But there may be two places I really like around the corner from my new building.
Now, marriage… If become married, I expect to forgo some opportunities for romance and sex. But the reason I am committing is precisely because the commitment, like getting to Ohio in order to get to Indiana, is a necessary step to other exciting opportunities. If I am NOT married, then, in this trivial sense of freedom, I am not free to experience the benefits of marriage. Conceiving a child with my wife, for example, is not now in my set of opportunities. A good commitment is precisely one in which the door you close behind you leads to several more that open.
Of course, to bring the trivial formality of this idea of freedom to the fore, it's also true that conceiving a child with my slave isn't in my set of opportunities, given the fact that I cannot own a slave. And every time a state strikes down an archaic law, like a law that says you can't bring a chicken into a saloon, people there will no longer be free to break the law by carrying chickens into saloons. However, as compensation, they will be free to legally carry chickens into saloons.
So, if freedom is just an increase in the size of the feasible set, then it simply doesn't follow that commitment diminishes freedom in this sense. So why say that “social ties actually decrease freedom, choice, and autonomy?”
This only makes sense, I think, if one commits the Stirnerite fallacy, which is the claim that any obligation whatsoever erodes freedom. The fallacy is named for Max Stirner, author of The Ego and It's Own, who argued that even the rules of language and logic are intolerable constraints on the fully free self. If you make a promise today, and don't want to keep it tomorrow, then DON'T! That would be self-enslavement!
Schwartz is the modus tollens to Harry Browne's libertarian Stirnerist modus ponens. Both agree that if you assume an obligation, then you are unfree. Browne advises us to avoid falling into the “trap” of assuming obligations. Schwartz advises us to be wary of too much freedom. Schwartz tells us we'll be less free if we're married, but we'll be miserable if we don't forge this kind of deep social bond. Browne tells us to not get married.
But we can be smart, and just reject the common assumption and understand the assumption of obligation and commitment as an expression of freedom that can also enhance freedom. And thus we can resist the inference(a non-sequitur anyway) that if freedom in the Stirnerite sense is good or bad, then it's good or bad for the political-economic system to offer us more or less of it.